Wind does not blow all the time nor does sun shine consistently. Battery storage has, therefore, become an essential component of a transition from dirty fossil fuels to clean renewables, from utility-scale installations to the individual home and vehicle. While hydro, biomass, and thermal are all examples of energy storage, the battery is currently the key component that will make electricity derived from clean and renewable but intermittent sources like solar and wind available where and when it is needed.
Energy storage is also critical in meeting electricity demand during peak times, such as on hot summer days when air conditioners are blasting or at nightfall when households turn on their lights and electronics. Energy storage allows greater grid flexibility as distributors can buy electricity during off-peak times when energy is cheap and sell it to the grid when it is in greater demand.
In California, the most populous state and a leader in environmental initiatives, the state’s Public Utilities Commission adopted a mandate to procure 1,325 megawatts of energy storage in 2013. To date, the CPUC has approved procurement of more than 1,533.52 megawatts of new storage capacity, with 506 megawatts already operational.
Energy storage will play a crucial role in meeting aggressive renewable-energy targets, according to the New York State Energy Research and Development Authority, or NYSERDA. These include a mandate to derive as much as 70 percent of the state’s electricity from renewable sources by 2030 and 100-percent carbon-free electricity by 2040. “Storage will help to integrate clean energy into the grid,” and also “stabilize supply during peak electric usage,” according to NYSERDA.
Battery storage can reduce demand on the grid, provide emergency backup for residential electricity, and deliver 100-percent clean energy if charged by solar panels or another renewable source, replacing the need for fossil fuel-fired “peaker plants” that operate as needed to meet peak energy demand.
State-level mandates like New York Gov. Andrew Cuomo’s 2019 allocation of $55 million for commercial and residential energy storage projects for Long Island will “drive down costs and scale up the market for these clean energy technologies.” The proliferation of residential solar and electric vehicles (EVs) has also spurred that of residential battery storage. Multiple EV manufacturers are among those following Tesla’s lead in offering home batteries, many of them available in the United States.
The price for lithium ion batteries, the leading energy storage technology, remains high, however, even as prices for solar and wind diminish. So researchers are exploring other alternatives, including flow batteries, thermal batteries, and gravity-based systems. The size of the energy storage market is predicted (as of 3/14/2020) to be $620 billion in investment by 2040.